They will have more "energy" on paper as they have more mass, especially if you increase the powder charge slightly to keep them at the same MV as a round ball.
In a recent thread we talked about a Hornady PA Conical bullet, made for a "slow twist" barrel, and the accuracy was not nearly as good as a patched round ball from the same test barrel...So... you'll have to test them to be sure from your rifle.
(iirc) They were marketed as a quick reload for a slow twist barrel for one could load and fire without using a patch. The problem is that no matter how fast you reload... you're very unlikely to get a "quick" second shot at, let alone hit, the deer you shot first, unless you are shooting a double barrel rifle of some sort. You are more likely to have time to properly reload a patched round ball, and then go looking for the deer (you should wait 15-20 minutes) If a second shot is needed you will have your most accurate round ready.
LD